American Oil and Gas Reporter - June 2015 - 81

SpecialReport: Artificial Lift Technology

Artificial Lift Tech Continues Evolving
By Corinne Westeman

The science of artificial lift has evolved
dramatically, driven by operational challenges ranging from high-pressure/hightemperature deepwater oil reservoirs to
liquids loading in natural gas wells producing below the critical rates and pressures needed to keep wellbores unloaded.
Arguably the biggest step changes in
artificial lift technology, however, are
being driven by the proliferation of horizontal wells in onshore resource plays,
with their characteristic multiphase flow
regimes and steep decline curves, according to Lloyd Heinze, a professor of
petroleum engineering at Texas Tech
University and executive director of the
Southwestern Petroleum Short Course.
While more than 95 percent of all
U.S. oil wells require some form of artificial lift (as do increasing numbers of
gas wells), Heinze says future advances
will revolve around two key challenges:
* Lifting the full liquid contents of
long horizontal well sections as operators
continue to extend lateral lengths; and
* Separating water down hole so that
it does not have to be lifted to surface
and then either disposed of or treated
and recycled.
"The growth of horizontal wells in
multiwell pads in liquids-rich shale plays
already is, and likely will continue to be,
the driving force of innovations in the
artificial lift sector," he states. "Sucker
rod pumping is limited in horizontal
wells, and both jet pumps and electric
submersible pumps can be limited in
these applications as well."
Because of the limitations of the
various types of pump systems, operators
in many plays implement multiple forms
of artificial lift at different points in a
well's production cycle. For example,
Heinze notes, in Permian Basin tight oil
plays such as the Wolfcamp, a well may
be equipped initially with a jet pump or
ESP to accommodate high flush rates, but
then be converted to gas lift after a few
months, and then to beam pumping after
that, when production has declined to an
optimal level for rod pumping.
"Artificial lift companies and operators
will have to work together to figure out
technologies that can pump the horizontal
sections of the well faster and more effectively," Heinze comments.

Downhole Separation
Similar in theory to solutions for downhole gas/liquids separation, but more complex in practice, economic downhole
oil/water separation (DOWS) has long
been a key objective for both operating
companies and equipment manufacturers.
There have been applications of different
DOWS configurations in North America,
but the technology remains a moving target.
The idea, according to Heinze, is to
separate water from oil using an in-well
hydrocylone or gravity separation device,
and then pump the oil to surface while
directing the water within the same wellbore to an injection zone either above or
below the productive zone.
"Treating and disposing produced and
flowback water represents a significant
cost for operators, especially in shale
plays," Heinze says. "Effective downhole
oil/water separation would greatly reduce
the cost associated with handling water
in these plays, and also might allow additional oil to be recovered, helping increase
estimated ultimate recoveries in low-permeability unconventional formations."
In the meantime, oil and gas companies' quest to improve asset performance,
boost production economics, and maximize EURs is sparking innovations across
all types of artificial lift technology and
in applications as diverse as horizontal
resource plays and deepwater developments. They include:
* High-efficiency beam pumping units

with optimized stroke geometries;
* High-durability jet pumps;
* Automation and surveillance systems for both surface and downhole
pumps;
* Stronger and lighter-weight sucker
rods for challenging well conditions;
* High-pressure and high-temperature
connections for ESPs; and
* High lift-capacity hydraulic pumping units.

Beam Pumping
Don Crow, vice president of sales at
Liberty Lift Solutions, says his company
is expanding its high-quality beam pumping product line to include both the high
efficiency (HE™) unit and an enhanced
geometry (EG™) design.
"Horizontal wells have changed the
nature of the pumping unit business,"
Crow suggests. "We started as a beam
pump manufacturer, but as horizontal
drilling evolved, we expanded into gas
lift and jet pumps to keep up with operator
needs."
Both the HE and EG beam pumping
units are engineered to meet the demands
of horizontal applications. For example,
he says, the HE units have 186 degrees
of upstroke rather than the 180 degrees
common on conventional pumping units,
giving them higher efficiencies because
of the longer upstroke.
However, Crow says the new EG configuration offers optimum mechanical efficiency during the pumping cycle up-

Liberty Lift Solutions' beam
pumping units offers both a
high efficiency (HE™) and an
enhanced geometry (EG™) design. Both types of units are engineered to meet the demands
of horizontal applications, but
the newer EG model includes a
192-degree crank rotation.

JUNE 2015 81
American Oil and Gas Reporter - June 2015

Table of Contents for the Digital Edition of American Oil and Gas Reporter - June 2015
